Various types of inhalers exist for aerosolizing liquids. For example, U.S. Pat. No. 5,586,550, incorporated herein by reference, describes an inhaler that includes a dispensing apparatus in which a membrane with tapered apertures is vibrated such that liquid in contact with a rear face of the membrane is dispensed from a front face of the membrane as an aerosol.
While effective at nebulizing liquids, such inhalers may not be particularly suited for certain applications, such as aerosolizing unit doses of insulin for pulmonary delivery. Additionally, such inhalers may employ less than optimal methods with respect to liquid delivery to the dispensing apparatus, dose control, and microbial control.
Hence, improved approaches with respect to aerosolizing doses of insulin for pulmonary delivery, liquid drug delivery to the dispensing apparatus, dose control, and/or microbial control between doses are desirable.